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Linear increases in BOLD response associated with increasing proportion of incongruent trials across time in a colour Stroop task

Mitchell, RLC


RLC Mitchell


Selective attention is popularly assessed with colour Stroop tasks in which participants name the ink colour of colour words, whilst resisting interference from the natural tendency to read the words. Prior studies hinted that the key brain regions (dorsolateral prefrontal (dlPFC) and anterior cingulate cortex (ACC)) may vary their degree of involvement, dependent on attentional demand. This study aimed to determine whether a parametrically varied increase in attentional demand resulted in linearly increased activity in these regions, and/or whether additional regions would be recruited during high attentional demand. Twenty-eight healthy young adults underwent fMRI whilst naming the font colour of colour words. Linear increases in BOLD response were assessed with increasing percentage incongruent trials per block (0, 20, 40, 60, 80, and 100%). Whilst ACC activation increased linearly according to incongruity level, dlPFC activity appeared constant. Together with behavioural evidence of reduced Stroop interference, these data support a load-dependent conflict-related response in ACC, but not dlPFC.

Journal Article Type Article
Publication Date May 1, 2010
Deposit Date Apr 30, 2012
Journal Experimental Brain Research
Print ISSN 0014-4819
Electronic ISSN 1432-1106
Publisher Springer
Peer Reviewed Peer Reviewed
Volume 203
Issue 1
Pages 193-204
Keywords Stroop task, fMRI, Selective attention, Conflict, Parametric study design.
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